1. Field of the Invention
The present invention relates to a digital camera comprising a smear removal function, more particularly to a digital camera which can change presence of smear removal or intensity of smear removal according to the smear generation state.
2. Description of the Related Art
For the past number of years, in image pickup devices such as a CCD, there has been a problem that a white line called smear is generated in the imaged image data due to entrance of intense light (for example, sunlight, car headlight and the like), leading to deteriorated image quality.
In order to solve such a problem, there have been digital cameras which remove smear by subtracting pixel signals in the vertical optical black region from pixel signals of pixels in the effective pixel region among pixel signals imaged by a CCD (for example, Japanese Laid-Open Patent Publication No. 2001-86413).
According to the traditional imaging apparatuses, image data with no smear can be obtained by subtracting pixel signals of pixels in the vertical optical black region from pixel signals of pixels in the effective pixel region.
However, in this case, there has been a problem that since the pixel signals of the pixels in the vertical optical black region are subtracted uniformly, deterioration of the signal-noise ratio or deterioration of image quality is caused in the case that smear is not generated intensely.
Further, in the case that smear is generated diagonally due to movement of the camera or an object, there has been a problem that deterioration of image quality is also caused when the pixel signals of the pixels in the vertical optical black region are uniformly subtracted.